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"Sheriff Joe" says he will continue to investigate the false "birther" claim

Arpaio dismissed political pressure to drop the issue and distanced himself from Trump's reversal

(CNN)Donald Trump has said he now believes President Barack Obama was born in the United States -- but one of his most prominent supporters says he isn't giving up on the investigation and doesn't know "how it's going to turn out."

Joe Arpaio, the controversial Maricopa County Sheriff from Arizona and strident opponent of illegal immigration, spoke Tuesday night to a meeting of the Surprise Tea Party Patriots, the group that initiated Arpaio's quest to prove that Obama was born outside the US. And according to a report from the Arizona Republic, he made clear he would continue.

"I'm not going to give up, and we're looking into it," he told the group. "I don't know how it's going to turn out."

"I don't care where he's from. We are looking at a forged document. Period," he said, according to the report.

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The man known as "Sheriff Joe" actually said that he had "nothing to do with Trump on the birth certificate." He told the group, "We did it on our own, because of you guys."

And Arpaio said that despite political pressure to drop the issue, he would persevere. "I know all the politicians say, 'Sheriff Joe, don't talk about it.' But how can I back down when we started it? I'm not going to just forget it."

Arpaio has served as a prominent supporter and surrogate for the Trump campaign, appearing with the candidate during campaign stops in Arizona and even speaking on behalf of Trump at the Republican National Convention over the summer.